build(deps): bump protobuf in /Traffic-Sign-Detection

Bumps [protobuf](https://github.com/protocolbuffers/protobuf) from 3.14.0 to 3.15.0.
- [Release notes](https://github.com/protocolbuffers/protobuf/releases)
- [Changelog](https://github.com/protocolbuffers/protobuf/blob/master/generate_changelog.py)
- [Commits](protocolbuffers/protobuf@v3.14.0...v3.15.0)

---
updated-dependencies:
- dependency-name: protobuf
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

Traffic-Sign-Detection/requirements.txt

@@ -71,7 +71,7 @@ Pillow==9.0.0
 pooch==1.3.0
 prometheus-client==0.9.0
 prompt-toolkit==3.0.10
-protobuf==3.14.0
+protobuf==3.15.0
 pyasn1==0.4.8
 pyasn1-modules==0.2.8
 pycparser==2.20